Opacity Control for Google Maps v3 Overlay

An opacity control / transparency slider inspired by Klokan Petr Přidal's original Opacity Control for Google Maps (v2) Overlay. Borrowing from the original design but completely re-coded to work with the radically different Google Maps API v3.

Originally developed for use on NZ Topo Map, the essential components have been cleaned up and extracted for easy re-use in your own web sites.

The example code provided serves tiles up from a single location but MapTiler and GDAL2Tiles generate a hierarchical set of tiles by default. It's very easy to adapt the code simply swap the - chars in the tile file name for / chars, reconstructing the original hierarchy structure.